In my widget, Vnode meta node information cannot be fetched when Vnode is child to a widget

[michaelgsy-zz]

Hi All,

In my widget, Vnode meta node information cannot be fetched when Vnode is child to a widget.
Does it bug, or have other solution?
Sample:

https://codesandbox.io/s/4lqo0w4nzx

description:

if drag "drag me", "Delta" can not show any position. you can debug it. this.meta(Drag).get(key) is return null.

[agubler]

This will now work with the new vdom (#58)